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I am a new member on here. I just recently bought a used 2007 X3si with 39,000 miles on it. The car as of todays date runs like a dream. Very quiet and very smooth. However, Ive noticed last night that when I turn off the car I can hear a short squeal like sound coming from underneath the rear end somewhere. Its kinda hard to tell how far in the rear end its coming from. It sound as if like 2 pieces of metal rubbing each other with no lubrication.

Does anyones X3 make that sound when the car turns off? Could it be the exhaust/muffler? transfer case? please dont say its the transfer case

Is you parking brake on? If my parking brake is on, sometimes when you get out of the car, it will rock and the (rear) brake will give a short metal on metal sounding squeak.

Thanks for your reply. Sorry, I should have mentioned that I have an automatic transmission. No lights display on my dash, everything runs smooth and quiet. No idea where that sound is coming from. It sounds like its coming right underneath the back seat area. I am a rookie with this car, i dont know as much yet..

Went home and had someone turn off the car for me and heard the noise right through the muffler. Im a rookie and know nothing about x3's but what is that valve like thing inside the muffler tips? I believe that made the noise. Is that normal? Thanks.

I periodically hear that same noise emanating from the rear of my 2007 X3. It is the fuel tank venting. Yes I realize it's a closed system but the tank vents into a carbon canister and what you are hearing is the valve operating allowing pressure to bleed off of the fuel tank.

I periodically hear that same noise emanating from the rear of my 2007 X3. It is the fuel tank venting. Yes I realize it's a closed system but the tank vents into a carbon canister and what you are hearing is the valve operating allowing pressure to bleed off of the fuel tank.

Hi. I figured out what it was. Its my butterfly valve inside my muffler. It opens everytime you turn off the car. It may be rusting or something that causes it to squeal like that. I never had a chance to try putting some grease on there.